Bedside tables which may be raised and lowered have been utilized in hospitals and similar situations in which it is desirable to have a table which may be utilized by a person in a bed or chair. Such bedside tables have been conventionally constructed of a base having an upstanding post-like structure at one end and a tabletop with a support mounted on the upper end of the post-like structure to support the tabletop. A locking mechanism cooperable with the post-like structure and support permits the tabletop to be releasably locked with respect to the base in any vertical position throughout its range of movement.
Various locking mechanisms have previously been developed, for example the conventional locking mechanism shown in FIGS. 2-4 of the present application and described in detail hereinafter. A similar locking arrangement is disclosed in U.S. Pat. No. 3,999,492, the subject matter of which is hereby incorporated herein by reference. These prior locking mechanisms have provided a locking effect which is adequate for their intended purposes. However, they have not been satisfactory in all respects.
For example, they typically require several separate metal parts which must be fabricated separately and which are relatively expensive to fabricate. Further, the number of parts involved has made it relatively difficult to assemble the locking mechanism during manufacture of the table, thereby increasing the amount of labor required to assemble each table and thus the production cost of the table. Moreover, they typically require at least two separate springs for proper operation, which also increases costs.
It is thus an object of the present invention to provide an improved locking mechanism which functions as well as the prior mechanisms but which has fewer parts and cheaper parts and which is relatively simple to assemble.
It is a further object of the present invention to provide an improved locking mechanism, as aforesaid, which requires only one spring for proper operation.
It is a further object of the present invention to provide an improved locking mechanism, as aforesaid, which is rugged and durable and requires little or no maintenance.